I think that your Patrick McSweeney (b. ~1786) was my g-g-g-grandfather.I haven't been able to trace Patrick McSweeney back to Ireland, so the fact that he came from Cappamore in 1827 will be a help.
I do know that he had a son Patrick Sweeney(b. ~1822 in Ireland) who was my g-g-grandfather.I believe that Patrick was his child by his first wife, whose name I have not yet found.
I don't know how much you've found out about the McSweeneys in New York.According to information from the 1860 census for Clinton Township, County of Clinton, NY - Jane Spellman was born in Ireland ~1810, which would have made her about 24 years younger than Patrick McSweeney.They had a son John (b. ~1844) who lived with them at the time of the census.
I think that there's a connection here and would like to exchange information with you.